A look at what would dare take on the ocean's deadliest predator, why a spider lights up like a Christmas tree, and why a wild animal begins to deliver unwanted newspapers like a paperboy.
Professor David Scheel takes an octopus into his home to learn about its intelligence and the extraordinary relationship he and his daughter develop with the creature. Named Heidi, the octopus is seen unravelling puzzles, recognising individual humans and even watching TV with the family. The film also looks at the remarkable behaviour of other octopuses around the world, from those that can change their colour and texture in a split second to the octopus that carries around its own coconut shell to hide in.
Dr Helen Czerski examines the hottest natural phenomena on the planet - lightning. Bolts of lightning five times hotter than the surface of the sun strike our planet over 3 million times every day - and yet we still know little about this deadly force of nature. Now, specialist photography is revealing how lightning travels through the air, high-speed cameras are unlocking the secrets of upward lightning that's triggered by our urban landscapes, and scientific expeditions are capturing rare images of intense electrical discharges over 80 kilometres wide.